Was it a guarantee she was going to lose? Was she not a renowned and battle-tested Jedi Master? It seems cowardly for a Jedi Master to run away from a fight, especially when it results in the inevitable deaths of all of the younglings. For someone worried about spreading her teaching/knowlege of the force, you would think the lives of the younglings would matter to her enough to try and protect them.

She definitely would have been killed, she may have put up a fight though. Anakin was the prophesized "chosen one", and was the reason Palpatine set him up to become his apprentice in the first place, Vader wasn't ever "beaten" until Episode VI by his own son, but even then Anakin left the darkside.